On July 3,2014,the world leading scientifi c journal Nature published a breakthrough in lipopolysacharride biogenesis entitled'Structural basis for lipopolysaccharide insertion in the bacterial outer membrane'...On July 3,2014,the world leading scientifi c journal Nature published a breakthrough in lipopolysacharride biogenesis entitled'Structural basis for lipopolysaccharide insertion in the bacterial outer membrane'.In this paper,a research team from the CAS Institute of Biophysics,led by structural biologist HUANG Yihua,announced their展开更多
Lipopolysaccharide （LPS）, also termed endotoxin, is a main component of the external leaflet of the outer membrane （OM） in Gram-negative bacteria. It serves as a natural bar- rier against harsh environments and to...Lipopolysaccharide （LPS）, also termed endotoxin, is a main component of the external leaflet of the outer membrane （OM） in Gram-negative bacteria. It serves as a natural bar- rier against harsh environments and toxic compounds, in- cluding antibiotics, and partially confers drug-resistance in bacteria [1]. LPS is also a powerful activator of inflamma- tion and innate immune responses in mammalian cells. For the discovery of LPS receptor, Toll-like receptor 4 （TLR4）, Bruce A. Beutler won the Nobel Prize in Physiology or Medicine in 2011. As LPS is essential to most Gram- negative bacteria, intervening in LPS biogenesis offers great opportunities for developing novel antibiotics against path- ogens. However, for a long time, it is unclear how LPS is transported across the periplasm （the space between the inner and outer membranes） and assembled in the external leaflet of the OM in Gram-negative bacteria. With the funding support from the Ministry of Science and Technol- ogy of China, National Natural Science Foundation of Chi- na and the Strategic Priority Research Program of the Chi- nese Academy of Sciences, structural biologist Yihua Huang and his colleagues at the Institute of Biophysics, Chinese Academy of Sciences, recently determined the crystal structure of the LptD/E complex from the pathogen Shigella flexneri [2]. This new membrane protein complex structure provides crucial insights into an essential step of LPS biogenesis and also provides us a novel target for de- veloping new antibiotics against Gram-negative pathogens.展开更多
目的：建立血小板外膜蛋白复合物（outer membrane protein complex，OMPC）的攫取方法，为研制具有临床诊断价值的多克隆抗体提供依据。方法：分别以DTT裂解法、SDS破碎法、NP-40裂解法和TritonX-100裂解法提取血小板膜抗原，利用SDS-P...目的：建立血小板外膜蛋白复合物（outer membrane protein complex，OMPC）的攫取方法，为研制具有临床诊断价值的多克隆抗体提供依据。方法：分别以DTT裂解法、SDS破碎法、NP-40裂解法和TritonX-100裂解法提取血小板膜抗原，利用SDS-PAGE电泳、动物实验、蛋白免疫印迹分析和ELISA评价裂解效果和免疫原性。结果：在4种方法中，TritonX-100裂解法效果最好，其主要含有分子量从50．160kD的几乎所有血小板膜糖蛋白和少量小分子的蛋白。结论：TritonX-100裂解血小板获得的OMPC溶解性好、免疫原性强，具有广泛的抗原交叉反应性，以此作为动物免疫或作为偶联多糖抗原的载体具有很好的应用前景。展开更多
内质网膜蛋白复合物亚单位6(endoplasmic reticulum membrane protein complex subunit 6,EMC6),也称穿膜蛋白93(transmembrane protein 93,TMEM93)是我们首次报道的一个人类自噬相关分子。EMC6基因进化保守,表达广泛,在胃癌组织中表达...内质网膜蛋白复合物亚单位6(endoplasmic reticulum membrane protein complex subunit 6,EMC6),也称穿膜蛋白93(transmembrane protein 93,TMEM93)是我们首次报道的一个人类自噬相关分子。EMC6基因进化保守,表达广泛,在胃癌组织中表达下调或缺失。本研究利用构建的重组腺病毒5型EMC6(Ad5-EMC6)载体,感染胃癌细胞系BGC823和SGC7901,分析了其在肿瘤细胞的表达以及抗肿瘤活性。研究证明,Ad5-EMC6能够显著抑制胃癌细胞的克隆形成、细胞划痕修复、以及迁移和侵袭的能力。进一步的研究提示,Ad5-EMC6能够降低胃癌细胞局部黏着斑激酶(FAK)的Y576/577磷酸化水平,FAK下游的基质金属蛋白酶MMP2和MMP9的蛋白质水平也同时下调。在裸鼠的腹膜扩散模型中,Ad5-EMC6处理组的小鼠腹膜结节数量明显减少或缺失。这些研究数据提示,Ad5-EMC6介导的FAK信号灭活可能是其抑瘤活性的机制之一,其分子机制还需要进一步探讨。展开更多
膜蛋白质通过与其他蛋白质相互作用形成膜蛋白质复合物(Membrane protein complexes,MPCs)形式来行使重要的生物学功能,譬如参与细胞-细胞交流、信号传导与分子识别等。MPCs的功能异常会导致多种疾病的发生和临床治疗耐药等问题。研究完...膜蛋白质通过与其他蛋白质相互作用形成膜蛋白质复合物(Membrane protein complexes,MPCs)形式来行使重要的生物学功能,譬如参与细胞-细胞交流、信号传导与分子识别等。MPCs的功能异常会导致多种疾病的发生和临床治疗耐药等问题。研究完整MPCs的组装对于绘制全景式蛋白质-蛋白质相互作用网络,进而揭示膜蛋白质机器的功能具有重要意义。然而,由于MPCs的过表达和纯化仍面临巨大挑战,如何从细胞中实现MPCs的高效提取尤为重要。因此,亟需发展既可确保MPCs提取效率,并能保持其结构稳定性的提取方法。该文对现有MPCs提取方法及其应用进展进行了综述,并对其发展前景加以展望,以期为MPCs的功能解析提供技术支撑。展开更多
基金supported by grants from the Chinese Ministry of Science and Technologythe Strategic Priority Research Program of the Chinese Academy of Sciencesthe National Natural Science Foundation of China
文摘On July 3,2014,the world leading scientifi c journal Nature published a breakthrough in lipopolysacharride biogenesis entitled'Structural basis for lipopolysaccharide insertion in the bacterial outer membrane'.In this paper,a research team from the CAS Institute of Biophysics,led by structural biologist HUANG Yihua,announced their
文摘Lipopolysaccharide （LPS）, also termed endotoxin, is a main component of the external leaflet of the outer membrane （OM） in Gram-negative bacteria. It serves as a natural bar- rier against harsh environments and toxic compounds, in- cluding antibiotics, and partially confers drug-resistance in bacteria [1]. LPS is also a powerful activator of inflamma- tion and innate immune responses in mammalian cells. For the discovery of LPS receptor, Toll-like receptor 4 （TLR4）, Bruce A. Beutler won the Nobel Prize in Physiology or Medicine in 2011. As LPS is essential to most Gram- negative bacteria, intervening in LPS biogenesis offers great opportunities for developing novel antibiotics against path- ogens. However, for a long time, it is unclear how LPS is transported across the periplasm （the space between the inner and outer membranes） and assembled in the external leaflet of the OM in Gram-negative bacteria. With the funding support from the Ministry of Science and Technol- ogy of China, National Natural Science Foundation of Chi- na and the Strategic Priority Research Program of the Chi- nese Academy of Sciences, structural biologist Yihua Huang and his colleagues at the Institute of Biophysics, Chinese Academy of Sciences, recently determined the crystal structure of the LptD/E complex from the pathogen Shigella flexneri [2]. This new membrane protein complex structure provides crucial insights into an essential step of LPS biogenesis and also provides us a novel target for de- veloping new antibiotics against Gram-negative pathogens.
文摘目的：建立血小板外膜蛋白复合物（outer membrane protein complex，OMPC）的攫取方法，为研制具有临床诊断价值的多克隆抗体提供依据。方法：分别以DTT裂解法、SDS破碎法、NP-40裂解法和TritonX-100裂解法提取血小板膜抗原，利用SDS-PAGE电泳、动物实验、蛋白免疫印迹分析和ELISA评价裂解效果和免疫原性。结果：在4种方法中，TritonX-100裂解法效果最好，其主要含有分子量从50．160kD的几乎所有血小板膜糖蛋白和少量小分子的蛋白。结论：TritonX-100裂解血小板获得的OMPC溶解性好、免疫原性强，具有广泛的抗原交叉反应性，以此作为动物免疫或作为偶联多糖抗原的载体具有很好的应用前景。
文摘内质网膜蛋白复合物亚单位6(endoplasmic reticulum membrane protein complex subunit 6,EMC6),也称穿膜蛋白93(transmembrane protein 93,TMEM93)是我们首次报道的一个人类自噬相关分子。EMC6基因进化保守,表达广泛,在胃癌组织中表达下调或缺失。本研究利用构建的重组腺病毒5型EMC6(Ad5-EMC6)载体,感染胃癌细胞系BGC823和SGC7901,分析了其在肿瘤细胞的表达以及抗肿瘤活性。研究证明,Ad5-EMC6能够显著抑制胃癌细胞的克隆形成、细胞划痕修复、以及迁移和侵袭的能力。进一步的研究提示,Ad5-EMC6能够降低胃癌细胞局部黏着斑激酶(FAK)的Y576/577磷酸化水平,FAK下游的基质金属蛋白酶MMP2和MMP9的蛋白质水平也同时下调。在裸鼠的腹膜扩散模型中,Ad5-EMC6处理组的小鼠腹膜结节数量明显减少或缺失。这些研究数据提示,Ad5-EMC6介导的FAK信号灭活可能是其抑瘤活性的机制之一,其分子机制还需要进一步探讨。
文摘膜蛋白质通过与其他蛋白质相互作用形成膜蛋白质复合物(Membrane protein complexes,MPCs)形式来行使重要的生物学功能,譬如参与细胞-细胞交流、信号传导与分子识别等。MPCs的功能异常会导致多种疾病的发生和临床治疗耐药等问题。研究完整MPCs的组装对于绘制全景式蛋白质-蛋白质相互作用网络,进而揭示膜蛋白质机器的功能具有重要意义。然而,由于MPCs的过表达和纯化仍面临巨大挑战,如何从细胞中实现MPCs的高效提取尤为重要。因此,亟需发展既可确保MPCs提取效率,并能保持其结构稳定性的提取方法。该文对现有MPCs提取方法及其应用进展进行了综述,并对其发展前景加以展望,以期为MPCs的功能解析提供技术支撑。
